Stoker motor control



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STOKER MOTORCONTROL vFiled April s, 1931 2 sheets-sheet 1 May 10, 1932.

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Witwe@ May 10, 1932. w. w. HUDSON STOKER MOTOR CONTROL 2 Sheets-Sheet 2 Filed April 5, 1931 @wi/Immo Patented May l0, 1932;

WILLIAM WALTER HUDSON.

F SALT LAKE CITY, UTAH sroxnn moron common appucauon mea apra s, 1931. sel-1111 No. 527,604.

The invention relates to` improvements in stokers of a general type in which the fuel is fed from a hopper to a fire pot, andin which combustion air is supplied tothe lire by means of a blower, both the feeding means for the fuel, and the blower, or at least the latter, being driven by an electric motor. Heretofore, even when using a closure for the hopper provided with a fillingrdoor, there has been danger of back-blowing dust and asladen air discharging from the door, fin ing its way to floors above and soiling furnishingsfin addition to being a more or less dangerous" element on account of the existing coal gas. 4

The air discharged from the blower is of course under some pressure and while most of this air rises through the yfire and supports combustion, some of its blows rearwardly through the fuel-conducting means and consequently blows from the hopper upon opening of the door. It is the object of my invention however, to overcome `this diiculty by the provision of unique means for automatically breaking the circuit of the bloweroper ating motor when the hopper door is opened.

Thus, when refilling the hopper or opening its door for other reason, there is no danger of allowing the escape of a large quantity of gas and dusteladen air. I

With the foregoing in view, the invention resides in the novel subject matter hereinafter described and claimed, description being accomplished .by reference to the accompanying drawings.

Fig. 1 is a side elevation partly in section showing a Stoker for a furnace, said Stoke-r .embodying my improvements.

Fig. 2 is a top plan View partly in horizontal section.

Fig. 3 is an enlarged vertical sectional view substantially on line 38 of Fig. 2, the door and the motor-stopping switch being shown open in dotted lines.

45 lVhile one specific embodiment is herein illustrated, it is to he understood that within the scope of the invention as claimed, numerous variations may be made.

A stoker is shown embodying a hopper 4 450 having a fuel discharge pipe 5 leading to a` lmay be refilled. Provision is made for autofuel pot or tuyre 6, the fuel being fed through said pipe 5 by a screw conveyor, a plunger or any other preferred means driven by an appropriate train of operatingv connections, from anelectric motor 7. This motor also drives a. blower` 8 from which an. air-conducting'pipe 9 leads to an air jacket 10 around the fuel pot 6. From this jacket, the air escapes into the fuel as shown by the arrows in Fig. 1, most of the air ascending through the ire bed and sup orting combustion, whilesome of it return's t rough the pipe 5 into the hopper 4. To prevent this back-blown air and the dust and .gases entrained thereby,M from discharging into the furnace room or '55 the like, a closure 11 is provided for the upper end of lsaid hopper. This closure embodies two top portions 12 and 13, both of which incline to a ridge 14. The portion 13 is provided with an inclined door 15 whose upper end is hinged at 16 on a line parallel with the ridge 14. A suitable latch 17 is provided for the door and when said latch is released and the door opened, the hopper u matically stoppin the motor 7 whenever the door 15 is opene preventing discharge of dust and gas-laden air at that time.

In the present showing, an ordinary knife switch 18 is mounted upon the top portion 12 of the ho per closure 11` said switch being embodied 1n the circuit of the electric motor 7 The base 19 of the. switch is secured upon the top portion 12. and the contact-bridging blade 20 is inclined, the lower end of said blade being pivoted yat 21 while its upper end 22 is spaced above the ridge 14. A suitable push link 23 is disposed over the door 15 and is inc-lined, the upper end of said link being pivoted to the upper end 22 of the switch blade 20, as denoted at 24. `The lower end of the link 23 is pivoted at 25 to an upstanding bracket 26 which is secured to the door 15.

The switch and operating elements therefor, remain in the positions shown in full lines in Figs. 1, 2 and 3 under ordinary circumstances. but whenever the door 15 is opened as shown in dotted lines in Fig. 3, the link 23 pushes against the switch blade 20, thereby opening the switch and automatically l breaking the circuit of the motor 'l' to stop the blower 8. lt is thus insured that while the door stands open, no air, gas and dust can be blown from the hopper to cause trouble or inconvenience in one way or another. As soon as the door 15 is again closed, the switch .18 becomes automatically vclosed also, again vmay be insulated to confine the current travel to the desired path.

1. In a Stoker, a hopper having means for feeding fuel vto a tire-pot, a` blower having means for conducting combustion air to the lire-pot, an electric motor for driving said blower, a closure for said hopper to normally prevent discharge of back-blown dustladen air from said hopper, said closure embodying a normally closed door, av normally closed switch embodied iii the circuit of said motor, and means connectingr said door with said switch for automatically opening said switch when 'said'door is opened, thereby stoppingthe. motor and blower and prevent.- ing back-blowing of dust-laden air through the open door.

'2. Ina Stoker, a hopper having means for feeding fuel to a fire-pot, a blower having means'or conducting combustion air to the lire-pot., an electric motor for driving said blower, a closure for said hopper to normally prevent discharge of back-'blown dust-laden air from said hopper. said closure embodying a normally closed door, a normally closed switchmounted ou said closure and embodied in the circuit of said motor, and means con'- uecting said door with said switch for autoinatically opening said switch when said door is opened, thereby stopping the motor and blower and preventing back-blowing of dustladen` air through the open door.

In a stoker, a hopper having means for feeding fuel to a tire-pot, a blower having means for conducting combustion air to the tire-pot. an electric motor for driving said blower, a closure for said hopper to normally prevent discharge of back-blown dustladen air romsaid hopper, said closure embodying two top portions both inclined to a ridge, one ot said top portions having an upwardly swingable door whose upper end is hinged on an axis parallel with said ridge. a

switch embodied in the circuit of said motor and secured upon the other of said top poi'- tions, said switch having an inclined contactsol 

